A word ladder turns one word into another, one letter at a time. Change exactly one letter per step, keep every step a real word, never rearrange the letters that stay, and reach the target in as few steps as you can. Lewis Carroll devised the game in 1877 and published it as Doublets; it survives because the rules fit in a sentence and the difficulty scales from a child's puzzle to a research problem. Every ladder on this page was checked against this site's word list, step by step, and the step counts claimed are the true shortest distances in that list unless the page says otherwise.
First ladder: CAT to DOG, three steps
CAT → COT → DOT → DOG
CAT and DOG differ in all three positions, so three steps is the floor, and this ladder hits it: change the vowel, change the first letter, change the last. Notice that no step wastes motion. Every move fixes a position that was wrong, which is possible here only because COT and DOT happen to be words. In longer ladders they usually do not, and detours begin.
Second ladder: COLD to WARM, four steps
COLD → CORD → CARD → WARD → WARM
The classic. Four positions differ, four steps suffice, and again every step repairs a difference: CORD fixes the third letter, CARD the second, WARD the first, WARM the last. When a ladder runs along the floor like this, it feels inevitable in hindsight. It is worth knowing that a computer checking all 3,903 four-letter words in our list confirms that no three-step route exists, because COLD has no neighbour that is also a neighbour of anything close to WARM. Four is not just good. It is provably best.
Third ladder: HEAD to TAIL, five steps and a confession
HEAD → HELD → HELL → TELL → TALL → TAIL
This is Carroll's own famous pair, and the everyday route takes five steps: HEAD, HELD, HELL, TELL, TALL, TAIL. Honesty requires the confession: it is not the shortest. A four-step route exists in the list, HEAD, HEAL, HEIL, HAIL, TAIL, but it runs through HEIL, a German salute that most English players do not keep in their heads. The five-step ladder is the one worth learning, because every word in it is a word you already own. A ladder is a human artefact as well as a graph path, and the best one is the shortest one you can actually find and defend.
Fourth ladder: BLACK to WHITE, seven steps
BLACK → CLACK → CLICK → CHICK → CHINK → CHINE → WHINE → WHITE
Five letters, five differences, and still the true distance is seven. The route spends its two extra steps in the CH cluster: CLICK becomes CHICK so that CHINK and then CHINE (the backbone of an animal, or a ridge) can carry the word across to WHINE and home. The lesson generalises. When the direct repair steps are not words, the ladder detours through a neighbourhood, a cluster of similar words (here CLACK, CLICK, CHICK, CHINK) that lets you change letters in an order the direct route forbids. Skilled ladder players think in neighbourhoods, not in single steps.
How to solve your own
Four habits, in order. Count the differences first: the number of positions where start and target disagree is your floor, and a ladder at the floor is finished the moment you find it. Work from both ends: build one step down from the target as well as up from the start, and let the chains meet; a five-step ladder is two short problems, not one long one. Move vowels early: vowel changes open the most doors in English, because so many word families (the _AT, _ET, _IT sets and their kin) are one vowel apart. Mind the dead ends: some words are cul-de-sacs, one step from everything and two steps from nowhere; when a chain stalls twice in the same neighbourhood, back up two steps, not one. If you get thoroughly stuck, the Anagram Solver will not climb the ladder for you, but the Word Unscrambler shows every word your current step's letters can make, which is often the nudge a stuck chain needs.
The shape of the whole web
Stand back and a ladder game is a map. The 3,903 four-letter words in our list form a web where most words touch most others through short chains: 97.5% of them sit in one giant connected cluster, which is why the game almost always works. The exceptions are instructive. Sixty-five four-letter words (ABRI, a shelter; ADZE, a cutting tool; AHOY; AMOK; ANKH; AQUA) differ from every other word in the list in at least two letters, so no ladder can include them at all. They are islands. Carroll, who set his ladders by hand and by instinct, cannot have known the map's true shape. We can, and it says his instinct was sound: the game works because English, at four letters, is almost one piece.
Questions
Who invented the word ladder?
Lewis Carroll, the author of Alice's Adventures in Wonderland, devised it in 1877, reportedly for two young friends at Christmas, and published it in Vanity Fair in 1879 under the name Doublets. The game has carried both names ever since. Carroll was a mathematician, and the puzzle has a mathematician's shape: a graph problem disguised as a parlour game, a century before graph problems were fashionable.
Can any two words of the same length be connected?
No, and the word list proves it two ways. Sixty-five of the 3,903 four-letter words in our list (ABRI, ADZE, AHOY and AMOK among them) differ from every other word in at least two letters, so they have no legal first step at all; no ladder can touch them. And even well-connected words occasionally sit in separate clusters. The good news is statistical: 97.5% of four-letter words belong to one giant connected web, so a randomly chosen pair is very likely to have a ladder, though not always a short one.
What is the fewest steps a ladder can take?
Never fewer than the number of positions where the start and target differ, because one step changes exactly one letter. COLD and WARM differ in all four positions, and their ladder takes four steps: it is as short as arithmetic allows. BLACK and WHITE differ in all five positions but need seven steps, because no chain of real words spends every step fixing a difference. The gap between the floor and the true distance is where the game lives.
Are proper nouns and plurals allowed?
Plurals, yes: they are ordinary words, and several steps in the ladders on this page rely on ordinary inflected forms. Proper nouns, no, at least in the word list this site uses, which contains no names at all. House rules vary between publishers, and Carroll's own rules excluded proper names too. Whatever list you agree on, agree on it first: half of all word-ladder arguments are dictionary arguments in disguise.
Sources
- ENABLE word list (public domain): every ladder step was verified against the list's three, four and five-letter files, and the distances and web statistics (3,903 four-letter words; 65 with no neighbour; 97.5% in one cluster) were computed from those files on 28 October 2026: github.com/brokensandals/wordlists
- The checking method is described in full on How We Verify. The Carroll history follows Wikipedia's account of the game: en.wikipedia.org/wiki/Word_ladder.
Update log
28 October 2026: published, with all four ladders computed and verified on the same day.